Ageing lung cancer patients may be at increased risk of Cisplatin (Cp) nephrotoxicity, because of comorbidities leading to accelerated ageing of the kidneys. Therefore, the Cp-induced impairement of renal function was compared between no comorbidity (NC) and hypertension plus ischaemic heart disease (CD) patients or others having diabetes mellitus plus ischaemic heart disease (DMIH). In a preliminary study, glomerular filtration rate (GFR) was measured by clearance of technetium 99m-labelled diethylene-thiamine penta-acetate in 38 lung cancer patients with normal serum creatinine concentration ([creat]). Then, the incidence of nephrotoxicity was analysed retrospectively over 1st-4th cycles of Cp treatment among 242 lung cancer patients with initially normal [creat]. GFR was repeatedly estimated using calculated creatinine clearance. Pre-treatment GFR was 57 ± 3 mL·min⁻¹·m⁻² in those with normal (n = 15) and 42 ± 2 mL·min⁻¹·m⁻² in those with pathologically increased (n = 23) [creat] any time following their 2nd-4th Cp cycle (p < 0.05). The retrospective analysis revealed that Cp-induced nephrotoxicity developed in 7.5% of the NC (n = 80), in 20.9% of the CD (n = 110) and in 30.8% of the DMIH (n = 52) subgroups. Within the overall dropout rate from further Cp chemotherapy, nephrotoxicity was responsible in 14% of NC, 38% in CD and 75% in DMIH patients. A major portion of our ageing lung cancer patients suffered from comorbidities leading to reduced renal resistance to Cp nephrotoxicity.